Adriamycins and uses thereof

ABSTRACT

The known antitumor antibiotic adriamycin and its β-anomer, and the novel compounds, 4&#39;-epiadriamycin (both α- and β-anomers) are prepared by condensing a novel, reactive protected derivative of adriamycinone with reactive intermediates which are 1-halo-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxo (or arabino) hexopyranoses.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a new process for the synthesis of theknown antibiotic adriamycin and its β-anomer. The invention also relatesto the new compounds: 4'-epiadriamycin α-anomer, 4'-epiadriamycinβ-anomer and a mixture thereof as well as a process for preparing same.The new processes for preparing adriamycin and 4'-epiadriamycin involvesthe preparation and use of a new, reactive, protected intermediatederivative of adriamycinone, the aglycone of adriamycin which newderivative is also included within the invention. The new compounds ofthe invention, i.e., 4'-epiadriamycin (α- and β-anomers) as well as theknown adriamycin are useful in treating certain tumors in animals.

2. Description of the Prior Art

Adriamycin and its aglycone adriamycinone are well known compounds. Theyare, for example, described and claimed in British Pat. Nos. 1,161,278and 1,217,133 owned by the unrecorded assignee of this application.

SUMMARY OF THE INVENTION

The present invention provides, in one aspect thereof, a new process forpreparing adriamycinone glycosides. More specifically, the inventionprovides a process, which in one embodiment is used for preparing theknown compound adriamycin (IV), i.e.,7-0-(3'-amino-2',3',6'-trideoxy-αL-lyxohexopyranosyl)-adriamycinone,##STR1## and its β-anomer (V), i.e.,7-0-(3'-amino-2',3',6'-trideoxy-β-L-lyxohexopyranosyl)-adriamycinone,##STR2## by condensing a novel dioxolanyl protected derivative ##STR3##adriamycinone (IB) wherein R₁, R₂ and R₃ are independently selected fromthe group consisting of hydrogen and C₁ -C₄ alkyl; or R₂ and R₃ togetherwith the carbon atom to which they are bound may form a saturated orunsaturated ring of 3-8 carbon atoms, preferably, the dioxolanylderivative wherein each of R₁, R₂ and R₃ is methyl, i.e., the compoundhaving the formula (IC) ##STR4## with a reactive protected derivative ofdaunosamine (II), i.e., 3-amino-2,3,6-trideoxy-L-lyxohexose, ##STR5## toform the glycosidic linkage after which the protecting groups, i.e., thetrifluoroacetyl groups on the daunosamine and the dioxolanyl protectinggroup on the adriamycinone moiety of the glycoside are removed and theα- and β-anomers are separated. The novel dioxolanyl protectedderivatives of adriamycinone (IB) which are condensed with theduanosamine derivative are prepared by reacting adriamycinone (I)##STR6## or a C₁ -C₄ alkyl ester thereof with a compound of the formula##STR7## where R₂ and R₃ are independently selected from the groupconsisting of C₁ -C₄ alkyl or R₂ and R₃ together with the carbon atom towhich they are bound may form a saturated or unsaturated ring of 3-8carbon atoms, in the presence of an organic or inorganic acid, such asp-toluene-sulfonic acid or hydrogen chloride.

The reactive protected derivative of daunosamine which is condensed withthe adriamycinone derivative (IB) is the intermediate1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxohexopyranose(IIB) ##STR8## which is in turn obtained from the intermediate,2,3,6-trideoxy-1-trifluoroacetoxy-3-trifluoroacetamido-4-trifluoroacetoxy-L-lyxohexopyranose(IIA), ##STR9## compound (IIA) being in turn prepared by reactingdaunosamine (II) with trifluoroacetic anhydride.

This same process, in another embodiment is used for preparing the novelantibiotics 4'-epiadriamycin (VI), i.e.,7-0-(3'-amino-2',3',6'-trideoxy-α-L-arabinohexopyranosyl)-adriamycinone##STR10## and its β-anomer (VII), i.e.,7-0-(3'-amino-2',3',6'-trideoxy-β-L-arabinohexopyranosyl)-adriamycinone##STR11## as a mixture of the two anomers as well as each anomerseparately. To prepare 4'-epiadriamycin (VI) and its β-anomer (VII), thedioxolanyl protected derivative of adriamycinone (IB) is condensed, asdescribed above, with a reactive protected derivative of4'-epidunosamine (III), i.e., 3-amino-2,3,6-trideoxy-L-arabinohexose,##STR12## to form the glycosidic linkage, after which the protectinggroups on the adriamycinone moiety and on the 4'-epidaunosamine areremoved and the α- and β-anomers are separated. The reactive protectedderivative of 4'-epidaunosamine which, in this embodiment is condensedwith (IB) is,1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-arabinchexopyranose(IIIB) ##STR13## which is obtained from the intermediate,2,3,6-trideoxy-1-trifluoroacetoxy-3-trifluoroacetamido-4-trifluoroacetoxy-L-arabinohexopyranose(IIIA) ##STR14## compound (IIIA) being in turn prepared by reacting4'-epidaunosamine (III) with trifluoroacetic anhydride. Thus, it isclear that the only essential difference between the two embodiments isthe nature of the starting sugar which is reacted (in the form of areactive protected derivative) with the protected dioxolanyl derivative(IB) of the aglycone (adriamycinone (I)) to form the glycoside. In oneembodiment this sugar has the L-lyxose configuration and in the other ithas the L-arabinose configuration.

In another aspect, the invention provides the novel antibiotic endproducts (VI) 4'-epiadriamycin (α-anomer) and (VII) 4'-epiadriamycin(β-anomer) as well as the novel intermediates of the formula (IB), whichare protected dioxolanyl derivatives of adriamycinone, and which areused in the preparation of adriamycin and the novel 4'-epiadriamycin.

In a further aspect, the invention provides methods of using the novelantibiotic end products (VI) and (VII) in treating various mammaliantumors.

The process of the invention, as stated above, broadly comprisescondensing a protected derivative of adriamycinone (I), and inparticular, a derivative wherein the primary OH group of the side chainis protected, e.g., a dioxolanyl derivative of the formula (IB),preferably, the compound of the formula (IC), with a derivative ofdaunosamine (II) or 4'-epidaunosamine (III) to obtain thepharmacologically active glycosides (IV) (adriamycin) and (V) or (VI)and (VII). In practice, the hexose (II) or (III) must first beprotected, for example, by forming the tri-trifluoroacetyl derivatives(IIA) and (IIIA) and then converted into reactive derivatives, such asthe 1-halides and in particular, the 1-chloro derivatives (IIB) and(IIIB) which are suitable for condensation with the adriamycinonederivative (IB), or preferably, (IC). After the condensation reaction,the protecting dioxolanyl group on the adriamycinone moiety, and theprotecting trifluoroacetyl groups on the hexose are removed to yield thefree glycosides.

The 3-amino groups in the hexoses (II) and (III) must be protected withgroups that can subsequently be removed without further decomposition ofthe products which contain different chemically-sensitive groups. Thetrifluoroacetyl group meets this criterion since it can be readilyremoved by mild alkaline treatment.

The hexoses (II) and (III) also have to be converted into reactivederivatives that are endowed with sufficient stability to be used in thecondensation reaction with the protected adriamycinone (IB) or (IC). Theinstability of the 1-halo derivatives of 2-deoxysugars is welldocumented (W. W. Zorbach et al., Advances in Carbohydrate Chemistry,1966 21, 273). However, according to the invention, it has been foundthat if the 3-amino and the 1 and 4 hydroxy groups of the hexoses (II)and (III) are protected with trifluoroacetyl groups, thetri-trifluoroacetyl derivatives (IIA) and (IIIA) of the hexoses (II) and(III) can then be reacted with dry hydrogen chloride to give thecorresponding 1-chlorohexoses (IIB) and (IIIB). These latter compoundsare solid materials which can be stored for several days under anhydrousconditions.

The tri-trifluoroacetyl derivatives (IIA) and (IIIA) are prepared byreacting, under anhydrous conditions, the hexoses (II) and (III), eitheras such, or as the hydrochloride, with trifluoroacetic anhydride atabout 0° C in an inert solvent such as diethyl ether.

The 1-chloro derivatives (IIB) and (IIIB) are then prepared by reactingthe tri-trifluoroacetyl derivatives (IIA) and (IIIA), under anhydrousconditions, with anhydrous gaseous hydrogen chloride, in an inertsolvent, such as diethyl ether, at a temperature of about 0° C.

The reactive 1-chloro derivative (IIB) or (IIIB) is then reacted withthe protected adriamycinone derivative (IB) or (IC) to form theglycoside linkage, after which the projecting dioxolanyl andtrifluoroacetyl groups are removed and the product is separated into therespective α- and β-anomers. Alternatively, the α- and β- anomers can beseparated before removal of the protecting trifluoroacetyl groups.

The conditions under which the condensation reaction is effected aremodifications of the well known Koenigs-Knorr reaction (Conchie et al.,Advances in Carbohydrate Chemistry, 1957, 12, 157). This standardreaction contemplates the use of a wide variety of different reactionconditions such as temperature, solvent, catalyst and hydrogen chloride(or bromide) acceptor. However, ordinarily, an optimal set of conditionsis necessary to achieve a significant reaction rate. Since the use ofthe standard Koenigs-Knorr reaction conditions with the 1-haloderivatives of 2-deoxy sugars leads to the unwanted formation of thecorresponding glycals (Zorbach et al., supra), it is necessary,according to the present invention, to modify those conditions.

The procedure according to the invention therefore comprises reactingthe protected adriamycinone derivative (IB or IC), prepared as describedabove, with the 1-chloro-N,O-di-trifluoroacetyl derivative (IIB) or(IIIB) of hexose (II) or (III) in an inert organic solvent such aschloroform or methylene dichloride, under mild conditions, in thepresence of a catalyst comprising a mercuric halide, for example,mercuric bromide, a hydrogen chloride acceptor, for example, mercuricoxide, silver carbonate, silveroxide, cadmium carbonate, and adehydrating agent, for example, molecular sieve.

The reaction products, which is either a mixture of the glycosides (IV)and (V) or (VI) and (VII), wherein the adriamycinone moiety is protectedwith a dioxolanyl group and the sugar moiety is protected with thefluoroacetyl groups are then treated, in two steps, first with a dilutealkali, such as sodium hydroxide to effect removal of theN-trifluoroacetyl groups and second with a dilute acid, such ashydrochloric acid to effect hydrolysis of the cyclic ketal on the sidechain, i.e., the dioxolanyl group, to thereby obtain the final products(IV) and (V) or (VI) and (VII). The respective α- and β-anomers are thenseparated, for example, by fractional crystallization or chromatographictechniques.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is a graph showing the effect of a mixture of (VI) and (VII)on the rate of beating of mouse heart cells in vitro.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following examples are given to illustrate the invention without,however, being a limitation thereof. All parts given are by weightunless otherwise indicated.

EXAMPLE 1 Preparation of9-desacetyl-9-(2',2'-dimethyl-4'-methoxy-4'-dioxolanyl)-daunomycinone(IC)

One gram of adriamycinone (I) in 10 ml. of dioxane and 200 ml. ofchloroform was treated with 80 ml. of dimethoxypropane and 0.17 gm. ofp-toluenesulfonic acid. The resulting mixture was left standing for 24hours at room temperature, after which 0.34 gm. of sodium bicarbonatewas added and the mixture stirred for five minutes. The organic layerwas repeatedly extracted with water to neutrality, dried over anhydroussodium sulphate, filtered, and evaporated under reduced pressure. Theresidue was then placed on the top of a silicic acid column, and elutionwas effected using a 10:1 (by volume) chloroform:acetone solvent system.The main reaction product, which was identified by analytical thin layerchromatography (Rf = 0.38 using silica gel plates and the above solventsystem), is9-desacetyl-9-(2',2'-dimethyl-4'-methoxy-4'-dioxolanyl)-daunomycinone(IC) in the form of a mixture of epimers. Compound (IC) wascharacterized by NMR, IR and mass spectra, with the following resultshaving been obtained:

NMR (DCDl₃): 1.48 e 1.65 (CDCl_(s), geminal CH₃) 3.47 (s, CH₃ O-C(13) )4.0- 4.6 (m, C(14)H₂) 13.02 e 13.71 (two s, chelated OH at C-6 and C-11)

IR (KBr): carbonyl absorption band at 1725 cm.⁻¹ which is typical ofadriamycinone was absent.

MS (DIS): 486 m/e (M⁺)

454 m/e (M--32═M-CH₃ OH)

450 m/e (M--36═M--2H₂ O)

438 m/e (M--58═M--CH₃ COCH₃)

131 m/e substituted dioxolanyl

EXAMPLE 2 Preparation of1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxohexopyranose(IIB)

One gram of daunosamine (II) hydrochloride was suspended in anhydrousdiethyl ether and treated at 0° C. with 8 ml. of trifluoroaceticanhydride. After allowing the suspension to stand for 2 hours at 0° C.and 1 hour at room temperature, the solvent was removed under reducedpressure and the residue was crystallized from dichloromethane to yield1.1 g. of2,3,6-trideoxy-1-trifluoroacetoxy-3-trifluoroacetamido-4-trifluoroacetoxy-L-lyxopyranose(IIA), having a m.p. of 132°-134° C. and a mass spectrum m/e 391 (M-44),322 (M-113). 0.5 g of (IIA) in anhydrous diethyl ether was treated at 0°C. with anhydrous gaseous hydrogen chloride. After standing at +5° C.overnight, the solvent was removed in vacuo to yield1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxohexopyranose(IIB) as crystalline product. The NMR spectrum of (IIB) in CDCl₃ was asfollows:

1.22 δ (d, J = 6.5 Hz, 3H, CH₃),

2.05-2.70 δ (m, 2H, C(2)H₂),

4.46 δ (dq, J = 6.5 Hz and J<1Hz, 1H, C(5)H),

4.60-5.10 δ (m, 1H, C(3)H),

5.37 δ(c, W_(H) = 6.0 Hz, 1H, C(4)H),

6.29 δ(m, W_(H) = 6.5 Hz, 1H, C(1)H), and

6.37 δ (broad s, 1H, NH).

EXAMPLE 3 Preparation of adriamycin (IV) and its β-anomer (V)

A solution of 40 mg. of (IC) in 3 ml. of methylene dichloride wastreated with 80 mg. of mercuric oxide, 20 mg. of mercuric bromide andmolecular sieve (3 A, Merck). The mixture was stirred for one hour atroom temperature, after which there were added thereto, 40 mg. of (IIB),prepared as in Example 2. After two hours stirring, an additional 40 mg.of (IIB) were added, and stirring was continued for 6 hours more. Then,20 ml. of chloroform were added, and the suspension was filtered. Theclear solution was evaporated under reduced pressure to yield a residuewhich was dissolved in 15 ml. of 0.1N sodium hydroxide. After standingfor 30 minutes at room temperature, the pH of the aqueous solution wasadjusting to 8.4 with 0.1N aqueous hydrogen chloride. The aqueoussolution was repeatedly extracted with chloroform, and the combinedchloroform extracts were dried over anhydrous sodium sulphate, filteredand evaporated to a residue. The residue was taken up in solution with20 ml. of 0.1N aqueous hydrogen chloride and left standing at roomtemperature for 24 hours. An equal volume of chloroform was added and,under stirring, the pH was raised to 8.4 with 0.1N aqueous sodiumhydroxide. The final product, which was a mixture of adriamycin (IV)(α-anomer) and a second component which is the β-anomer of adriamycin(V) was recovered in the chloroform phase in a total yield of 80%.Adriamycin (β-anomer) (V) is also called 1'-(S)-adriamycin according tothe nomenclature of Cahm et al, Experientia, 1956, 12, 81. Evaporationof the chloroform solution to 0.5 ml., and the addition of a drop ofdilute methanolic hydrogen chloride causes the main product (adriamycin,α-annomer) (IV) to precipitation as the hydrochloride in crystallineform. -anomer) adriamycin hydrochloride (β anomer) has [α]_(D) ²⁰ + 463°(c = 0.07 MeOH) TLC on silica gel plat buffered at pH 7 (M/15phosphate), solvent system CHCl₃ --MeOH--H₂ O (130:60:10 by vol.), Rf =0.35.

EXAMPLE 4 Preparation of1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-arabinohexopyranose(IIIB)

One gram of 2,3,6-trideoxy-3-trifluoroacetamido-L-arbinohexopyranose,prepared in accordance with the description set forth in copendingapplication Ser. No. 560,105 filed Mar. 19, 1975, now U.S. Pat.4,039,663, issued Aug. 2, 1977, was suspended in 20 ml of anhydrousdiethyl ether and treated at 0° C. with trifluoroacetic anhydride. Afterallowing the suspension to stand for 2 hours at 0° C. and 1 hour at roomtemperature, the solvent was removed under reduced pressure and theresidue crystallized from dichloromethane to yield2,3,6-trideoxy-1-trifluoroacetoxy-3-trifluoroacetamido-4-trifluoroacetoxy-L-arabinohexopyranose(IIIA). The thus obtained (IIIA) was treated with anhydrous gaseoushydrogen chloride as described in Example 2 to give a quantitative yieldof1-chloro-2,3,6-trideoxy-3-trifluoro-acetamido-4-trifluoroacetoxy-α-L-arabinohexopyranose(IIIB). The NMR spectrum of (IIIB) in CDCl₃ was as follows:

1.30 δ (d, J = 6.0 Hz 3H, CH₃),

2.25-2.80 δ (m, 2H, C(2)H₂),

4.20-4.65 δ (m, 1H, C(5)H),

4.65-5.15 δ (m, 2H, C(3)H and C(4)H),

6.25 δ (m, W_(H) = 6.0 Hz, 1H, C(1)H), and

6.45 δ (broad s, 1H, NH).

EXAMPLE 5 Preparation of 4'-epiadriamycin (VI) and its β-anomer (VII)

A solution of 0.7 gm. of (IC), prepared as described in Example 1 in 35ml. of methylene dichloride was treated with 1.4 gm. of mercuric oxide,0.35 gm. of mercuric bromide and an excess of molecular sieve (3 A,MercK) as dehydrating agent.

The mixtures was stirred at room temperature, and two 0.35 gm. portionsof (IIIB) were added after 1 and 3 hours respectively. The stirring wascontinued overnight, after which 50 ml. of chloroform were added. Thereaction mixture was filtered and the filtrate was evaporated undervacuum to yield a residue which was dissolved in methanol, refluxed 15minutes and evaporated to dryness. The residue was dissolved in 50 ml.of 0.1N sodium hydroxide and 10 ml. of acetone. After 30 minutesstanding at room temperature, the pH was adjusted to 8.4 with diluteaqueous hydrogen chloride. The solution was then repeatedly extractedwith chloroform. The combined chloroform extracts were dried withanhydrous sodium sulphate, filtered, and evaporated under vacuum. Theresulting residue was taken up in 50 ml. of 0.1N aqueous hydrogenchloride and left at room temperature for 36 hours. The acidic solutionwas washed by extraction with chloroform to eliminate traces of theaglycone, and the brought to pH 8.6 with stirring and in the presence of50 ml. of chloroform by slowly adding 0.1N aqueous sodium hydroxide. Theorganic phase was separated, dried with anhydrous sodium sulphate, andconcentrated to 10 ml. Upon careful addition of methanolic hydrogenchloride, a red precipitate was obtained. The precipitate was collected,washed with diethylether and dried. The product, amounting to 220mg, wasa 70:30 (weight) mixture of 4'-epiadriamycin hydrochloride (α-anomer)(VI) and 4'-epiadriamycin hydrochloride (β anomer) (VII). The twoanomers as free bases were then separated by chromatography on a silicicacid column.

4'-Epiadriamycin hydrochloride (α-anomer), has m.p. 185° C (dec) [ _(D)²⁰ + 274° (c =0.01 MeOH), TLC on silica gel plat buffered at pH 7 (M/15phosphate), solvent system CHC1₃ --MeOH--H₂ 0 (130:60:10 by vol.) Rf :0.55.

4'-Epiadriamycin (β anomer) Rf : 0.43 (same conditions).

    ______________________________________                                           The following inhibition                                                   zones for the hydrochlorides of the below listed compounds were               obtained on agar-B-subtilis plates using the paper disc technique             (diameter given in mm.):                                                                     4'-epi-adriamycin;                                                                          4'-epi- 4'-epi-                                                 70:30 (mixture of                                                                           adriamycin                                                                            adriams                                       adriamycin                                                                              α- and β-anomers)                                                                (α-anomer)                                                                      (β-anomer)                          μg                                                                              (IV)      (VI) and (VII)                                                                              (VI)    (VI)                                     ______________________________________                                         5   --        19            19      15                                       10   21        21            21      15.5                                     15   --        22            22      16                                       20   23        23            23      17                                       ______________________________________                                    

BIOLOGICAL ACTIVITY

The antitumor activity of the novel compounds of the invention i.e,4ζ-epi-adriamycin, both as a 70:30 mixture of the α and β-anomers and asthe α-anomer alone was evaluated on several transplanted tumors in mice,and in vitro tests, in comparison with the known antitumor agentadriamycin. The results of these tests are given in the followingtables.

Ascites Sarcoma 180

The tests were carried out on groups of 10 mice (Swiss CD 1). Thecompounds under examination were administered intraperitoneally invarying doses to the test animals one day after intraperitonealinoculation with 1 ×10⁶ tumor cells per animal. The average survivaltime is given in Table 1 as a percentage of the survival time ofuntreated animals, which is arbitrarily designated as 100%. Also givenin Table 1 are the number of a long term survivors.

                  TABLE 1                                                         ______________________________________                                                Action on Ascites Sarcoma 180                                                                         Long Term Sur-                                          Dose    Average survival                                                                            vivors (after                                 Compound  mg/Kg   time (%)      60 days)                                      ______________________________________                                        control   --      100           0/30                                          Adriamycin                                                                              1       169           0/10                                                    5       276           2/10                                          4'-Epi-adriamy-                                                                         0.2     124           0/10                                          cin (70:30 mix-                                                                         1       247           7/30                                          ture of α and β-                                                             1.5     342           12/20                                         anomers)  2.25    345           9/20                                                    5       172           0/10                                          4'-Epi-adriamy-                                                                         0.5     135           0/10                                          cin (α-anomer)                                                                    2       184           0/10                                                    10      234           1/8                                           ______________________________________                                    

Transplanted Gross Leukemia

Inbred C₃ H/He mice were intravenously inoculated with 2×5 10⁶ leukemiacells/mouse and treated, intravenously, from the first to the fifth dayafter inoculation with the compounds under examination. The averagesurvival time percentage and the number of long term survivors are givenin Table 2.

                  TABLE 2                                                         ______________________________________                                                Action on Transplanted Gross Leukemia                                               Average Survival                                                                            Long Term Sur-                                            Dose  time (%)      vivors (after                                     Compound  mg/kg   Exp. 1   Exp. 2 60 days)                                    ______________________________________                                        Control   --                      0/30                                        Adriamycin                                                                              2       183             0/10                                                  2.5     208      186    0/20                                                  2.75    208             0/10                                                  3                186    0/10                                                  3.6              200    0/10                                        4'-Epi-adriamy-                                                                         2       133             0/10                                        cin (70:30 mix-                                                                         2.5     142      143    0/20                                        ture of α and                                                                     2.75    142             0/10                                        β-anomers)                                                                         3                157    0/10                                                  3.6              171    0/10                                        ______________________________________                                         L.sub.1210 Leukemia                                                      

Inbred BDF₁ mice were intraperitonealy inoculated with 10⁵ leukemiacells/mouse, and then treated (intraperitonealy) 5 times (every twohours) on days 1 and 2 after the tumor inoculation with varying doses ofthe compounds under examination. The average survival time percentageand the number of long term survivors are given in Table 3.

                  TABLE 3                                                         ______________________________________                                                Action on L.sub.1210 Leukemia                                                                        Long Term Sur-                                           Dose    Average Survival                                                                           vivors (after                                  Compound  mg/kg   time (%)     60 days)                                       ______________________________________                                        Adriamycin                                                                              0.75    160                                                                   1       155          1/10                                                     1.25    175                                                         4'-Epi-adriamy-                                                                         0.75    140                                                         cin (70:30 mix-                                                                         1       140                                                         ture of α and                                                           β-anomers)                                                               ______________________________________                                    

Solid Sarcoma 180

Swiss CD 1 mice were subcutaneously grafted with fragments of neoplastic(Solid Sarcoma 180) tissue and treated intravenously according todifferent schedules as shown in Table 4. The growth of the tumors wereevaluated by caliper measurement on the 10th day after the tumorimplants. The results, including tumor growth inhibition, and theaverage survival time percentage are given in Table 4.

                                      TABLE 4                                     __________________________________________________________________________    Activity on Solid Sarcoma 180                                                         Dose                                                                              Schedule of                                                                           % Inhibition                                                                         Average Sur-                                                                          Toxic Deaths                               Compound                                                                              mg/Kg                                                                             Treatment                                                                             tumor growth                                                                         vival time (%)                                                                        (at 10th day)                              __________________________________________________________________________    Adriamycin                                                                            1.25                                                                              Subcutaneously                                                                        69     112     0/10                                               1.75                                                                              every 2 hrs.                                                                          75     87      1/10                                               2.45                                                                              for 5 times at 32      6/10                                                   days 1 and 3.                                                     4'-Epi-adriamy-                                                                       1.25                                                                              "       31     105     0/10                                       cin (70:30 mix-                                                                       1.75        47     100     0/10                                       ture of α- and                                                                  2.45        61     97      0/10                                       β-anomers)                                                               Adriamycin                                                                            2.5 Intravenously                                                                         54             0/10                                               3.5 once a day on          7/10                                                   days 1,2,3,4,5.                                                   4'-Epi-adriamy-                                                                       2.5 "       31             0/10                                       cin (70:30 mix-                                                                       3.5         46             0/10                                       ture of α- and                                                                  4.5         43             0/10                                       β-anomers)                                                               Adriamycin                                                                            2   Intravenously                                                                         70     100     1/10                                               2.5 twice a day on                                                                        71     100     2/10                                               3   days 1,2,3.    57      6/10                                       4'-Epi-adriamy-                                                                       3   "       45     133     0/9                                        cin (70:30 mix-                                                                       4           57     106     0/10                                       ture of α- and                                                                  5           59     84      1/10                                       β-anomers)                                                               __________________________________________________________________________

Tests in vitro on the Formation of foci by Moloney Sarcoma Virus (MSV)

The test compounds were evaluated on mouse embryo fibroblast culturesinfected with MSV and on similar uninfected cultures. After a treatmentof three days, the inhibiting doses (ID₅₀) were evaluated on cellproliferation in uninfected cultures (cytotoxic action) and on MSV fociformation in infected cultures (antiviral action). The results obtainedare given in Table 5.

                  TABLE 5                                                         ______________________________________                                                    Antiviral Action                                                                            Cytotoxic Action                                                ID.sub.50 ν/ml                                                                           ID.sub.50 ν/ml                                   ______________________________________                                        Adriamycin  0.005         0.01                                                4'-Epi-adriamy-                                                                           >0.006        0.01                                                cin                                                                           ______________________________________                                    

Activity on MSV Production

MSV infected cultures were treated for three days, and the virus yieldswere determined in the cell and supernatant medium by focus assay in thepresence of lukemia virus. The results are given in Table 6.

                  TABLE 6                                                         ______________________________________                                        Compound    Dose (ν/ml)                                                                              FFU/ml                                              ______________________________________                                        Control                   4.7 × 10.sup.4                                4'-Epi-Adriamy-                                                                           0.05          4 × 10.sup.2                                  cin         0.0250                                                            ______________________________________                                    

Test in vitro on the Cloning Efficiency of HeLa cells

After treatment for 2,8 or 24 hours, HeLa cells were seeded (200 cellsper plate) and the number of colonies determined eight days later.

The ID₅₀ represents the dose which gives a 50% of inhibition ofcolonies. The results obtained are given in Tables 7 and 8.

                  TABLE 7                                                         ______________________________________                                                       Average Number of Colonies After                                       Doses  Treatment Periods:                                             Compound   μg/ml                                                                              2h        8h      24h                                      ______________________________________                                        Control   --       132       125     223                                      Adriamycin                                                                              1        21        8       0                                                  0.5      42        16      0                                                  0.25     46        38      20                                                 0.1      79        73      48                                                 0.05     100       96      76                                                          DI.sub.50 0.17                                                                          DI.sub.50 0.14                                                                        DI.sub.50 0.016                                             μg/ml  μg/ml                                                                              μg/ml                                 4'Epi-adria-                                                                            1        57        36      29                                       mycin (α-                                                                         0.5      101       92      52                                       anomer)   0.25     103       150     199                                                0.1      104       158     216                                                         DI.sub.50 0.85                                                                          DI.sub.50 0.7                                                                         DI.sub.50 0.36                                              μg/ml  μg/ml                                                                              μg/ml                                 ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                                       Average Number of Colonies After                                       Dose   Treatment Periods:                                             Compounds μg/ml 2h        8h      24h                                      ______________________________________                                        Control   --        156      189     136                                      Adriamycin                                                                              0.5      27        14      n.d.                                               0.25     92        28      43                                                 0.125    166       103     69                                                          DI.sub.50 0.35                                                                          DI.sub.50 0.18                                                                        DI.sub.50 0.125                                             μg/ml  μg/ml                                                                              μg/ml                                 4'-Epi-adria-                                                                           1        105       27      17                                       mycin (α-                                                                         0.5      130       45      38                                       anomer)   0.25     109       43      46                                                 0.125    245       170     100                                                         DI.sub.50 5                                                                             DI.sub.50 0.2                                                                         DI.sub.50 0.2                                               μg/ml  μg/ml                                                                              μg/ml                                 ______________________________________                                    

Tests in vitro on the Cardiotoxic Activity

The cardiotoxic activity of the test compounds was evaluated in vitro onmyocardial cells of BALB/c or CD 1 newborn mice (Necco A., Dasdia T.IRCS, 2 : 1293, 1974) Adriamycin causes a 50% decrease of beating in 2hours at a dose of 0.5 μ/ml.

4'-Epi-adriamycin (70:30 mixture of α and β anomers), at doses up to 5μg/ml did not substantially alter the beating rate. This is shown in thedrawing.

Variations can, of course, be made without departing from the spirit andscope of the invention.

Having thus described our invention, what we desire to secure by LettersPatent and hereby claim is
 1. A compound selected from the groupconsisting of 4'-epi-adriamycin (α-anomer), 4'-epiadriamycin (β-anomer)and a mixture thereof.
 2. A compound according to claim 1, which is4'-epiadriamycyn (α-anomer).
 3. A compound according to claim 1, whichis 4'-epiadriamycin (β-anomer).
 4. A compound according to claim 1,which is a mixture of the α- and β-anomers of 4'-epiadriamycin whereinthe α-anomer comprises about 70% by weight and the β-anomer comprisesabout 40% by weight.
 5. A method of inhibiting the growth of a tumorselected from the group consisting of Moloney Sarcoma Virus, Sarcoma 180Ascites, Solid Sacroma 180, gross transplantable leukemia and L.sub.1210 leukemia which comprises administering to a host afflicted withsaid tumor an amount of a compound selected from the group consisting of4'-epiadriamycin, α-anomer, 4'-epiadriamycin, β-anomer and mixturesthereof sufficient to inhibit the growth of said tumor.
 6. A methodaccording to claim 5, wherein the compound is administeredintravenously.
 7. A method according to claim 5, wherein the compound isadministered intraperitoneally.